Conveying apparatus for gas generators



Sept. 16, 1941. M. OBRIAN 2,256,407

CONVEYING APPARATUS FOR GAS GENERATORS Filed June 29, 1938 INVENTORMAURICE OBRIAN ATTO RN EY Patented Sept. 16, 1941 2,256,407 CONVEYINGAPPARATUS FOR GAS GENER- ATORS Maurice OBrian, Indianapolis, Ind.,assignor to The Prest-O-Lite Company, Inc., a corporation of New YorkApplication June 2 9, 193s, SerialNo. 216,444

8 Claims. This invention relates to conveying apparatus for gasgenerators, and more particularly to apparatus for safely conveyingfinely-divided material between the interior of a combustible gasgenerator and a point outside the generator. The principles of thisinvention are particularly applicable to the removal of dry calciumhydroxide or lime residue from a generator in which acetylene isgenerated through the reaction of water and calcium carbide in theprocess known as "dry generation.

The process of dry generation of acetylene consists principally ofagitating a moving body of calcium carbide and adding to the agitatedand moving body an amount of water necessary to react the carbidecompletely and also an additional amount which by being vaporizedreduces the temperature and so avoids a dangerous temperature risewithin the generator. In dry generation, calcium carbide and water arecontinuously introduced into a generating zone, while acetylene Y gasand the substantially dry residue are removed therefrom. Since thegenerated acetylene is discharged from the generating zone at asubstantial pressure, and water is introduced under pressure, it hasbeen necessary to introduce the vide such apparatus in which the columnof finely-divided material is maintained in a packed carbide into thegenerating zone by means of a 4 discharge hopper or receptacle, fromwhich it is conveyed to a lime storage bin or bins, and it has also beennecessary to remove the residue from the dry generator through a doublevalve or similar arrangement.

Such double valve arrangements for introducing carbide and for removingresidue have been necessary, since if acetylene escapes from thegenerator into the generator room or elsewhere, the fire and explosionhazard due to acetylene becoming mixed with atmospheric air isconsiderable. Furthermore, if in the introduction of car hide or in theremoval of the lime residue, air is admitted into the generator, anexplosive mixture of acetylene and air will be formed within thegenerator itself and similarly constitute a fire and explosion hazard.

Among the objects of this invention are to provide apparatus for safelyconveying a finely-divided material between the interior of acombustible gas generator and a point outside thereof by maintaining inan enclosed conveying conduit a column of finely divided material ofsufficient height to act as' a seal and thereby prevent an influx of airor escape of combustible gas; to procondition of greater density thanthat normally caused by gravity; to provide such apparatus by which sucha seal may be automatically maintained; to provide a hopper in which asealing column is maintained insuch a packed condition; to providepositive means for indicating 'the height of material in such a hopper;to provide a conveyor in which a gas-sealing column of finely-dividedmaterial of predetermined depth is automatically maintained; and toprovide other apparatus adapted to carry out this invention.

The above and other objects and novel features of this invention willbecome apparent from residue are produced. An annular lime overflow oraccumulating trough l extends completely around the inside of thegenerating chamber and receives finely-divided dry lime from theenclosed reaction zone. By means of an agitator or sweep 2, which servesto clean the bottom and sides of the annular trough I and thereby prevents the accumulation or incrustation of lime thereon, the dryfinely-divided lime within the trough l is swept through an outletopening 3 into a gas-tight lime receptacle or hopper 4, which isoperatively connected to the trough l of the generator. From an outlet 5of the hopper 4, the lime is conveyed through an enclosed path by ahorizontal conveyor H to a vertical conveyor V, and thence by thevertical conveyor through an outlet6 to a storage bin 3.. The hopper 4and horizontal and vertical conveyors provide an enclosed conduitbetween the reaction zone of the generator and a point outside thereof,such as the storage bin B.

The lime is moved through a housing l0 of the F horizontal conveyor by ahelicoid screw feeder H, which is turned by a shaft: I 2 journaled inbearings l3 and M. The lime is positively moved upwardly through ahousing l5 of. the vertical conveyor by a second helicoid screw feederI6 turned by a shaft H, the upper end of which isjournalled in asuitable bearing installed within generator hopper V. The bearing I4 isalso air-tight, and the bearing 13, as well as the bearing for the shaftII at the lower end of the housing i5, .is provided with suitablepacking to prevent escape of combustible gas or inflow of air.

The shaft i1 is rotated from the shaft I! by a suitable drive, whichincludes a chain 20 passing around sprockets 2| and 22, sprocket 2|being mounted on the shaft l 1, and sprocket 22 being mounted on astub-shaft 23, which is journalled in suitable bearings in a gear box24. Suitable gears, within the gear box 24, and operatively connectingthe shaft I1 and stub-shaft 23 complete the drive.

A suitable electrical driving motor (not shown) is connected to theshaft l 2, and may be run continuously or periodically'as desired, whileits control may be manual or automatic. Furthermore, the driving motormay have either a constant or a variable speed. To obviate thepossibility of any acetylene and air mixture present in the generatingroom becoming ignited due to sparks, this motor, as well as the verticalconveyor and storage bin, are placed outside the generator room. Thehorizontal conveyor H passes through a wall W of the generator room, anda plate 25 fitting snugly about the housing l and attached to the wall Wprovides a seal therefor.

To cause a slight packing of the lime dust and resulting density greaterthan that normally caused by gravity, thereby providing a more effectiveseal, the hopper 4, which constitutes an enlarged portion of theenclosed path through which the lime dust moves, tapers downwardly, i.e. decreases in cross-sectional area from top to bottom. In order toprovide a sufficient height of lime within the hopper to obtain aneffective seal, but without impeding the ischarge of additional limeinto the upper part of the hopper during continuous operation of the gasgenerator, the driving motor may be started when the lime reaches anupper predetermined level, and

stopped when it reaches a lower predetermined level. For positivelydetermining the height of lime in the hopper 4, a suitable indicator isutilized, such as a hunting disk 30 mountedat the lower end of a rod 31.The rod 3| passes through a ball and socket joint Jwhich includes a ball32, a pair of gaskets 33, a casing 34 attached to the hopper in asuitable manner, such as by welding, and acap 35 which clamps gaskets 33tightly against ball 32 to provide a more effective seal. A packinggland 36 seals rod 3|, and permits the'rod to be moved upwardly anddown- -wardly by a handle 31 to cause the hunting disk 30 to contact thebody of lime within the hopper 4, thereby indicating the lime levelwithin the hopper, such as at a lower predetermined level'L. Inaddition, through the ball and socket joint which permits lateralmovement in any direction as well as longitudinal movement of rod 3|,'disk 30 may be moved to contact the interior of the container at anypoint in order to remove any incrustation of lime.

If the sealbrovided in the hopper alone is utilized, it is normallynecessary to operate a constant speed driving motor periodically, butsuch a driving motor may be operated continuously when a continuous sealis automatically maintained at some point in the discharge path. Forthis purpose, the upper end 45 of the vertical 'screw feeder i6 isdisposedat a predetermined level which is a sufficient distance belowthe outlet of the vertical conveyor to provide a sealing section Swithin the vertical housing l5 in which housing 15 adjacent the outlet5, the plate 46 providing a positive guide for directing the lime intothe outlet, while a blade 41 mounted on shaft l1 sweeps the lime at thetop of the sealing section into the outlet.

To provide an auxiliary gas-tight seal at the outlet 6, when thegenerator is shut down or for any other reason, a disk 48 of suitablesealing material, such as rubber, is mounted on the end of a shaft 49.The shaft 43 extends through the conveyor housing, being disposedalongside the vertical shaft l1, and may be turned by a hand wheel 50 inthe generator room, the end of the shaft adjacent the hand wheel beingthreaded and cooperating with a fixed nut 5| to permit the disk 48 to bedrawn into sealing engagement with the outlet and thereby provide agas-tight seal. The shaft 49 passes through a, stufllng box 52 mountedin the housing l5, which provides a gas-tight seal at the point at whichshaft 43 passes through the housing l5; and the fixed nut 5| is providedwith a flange 53 attached to the wall W, which prevents the leakage ofany combustible gas through the opening in the wall W through which theaft 43 passes.

A normally gas-tight outlet is provided in a lime-sampler 55, attachedto the horizontal conveyor H, by means of which the operation of thegenerator may be checked by periodically removing samples of lime fromthe conveyor H and testing such samples. The sealing section S of thevertical conveyor housing I5 is provided with a normally gas-tightinspection hole 55, which may be covered by a metal plate, or may beprovided with a transparent window, so that the amount of lime withinthe sealing section may be observed to insure proper operation of thegen erator at all times.

The sealing section S in the vertical conveyor may be utilized alone toprovide a seal, or a double seal may be had'by utilizing also a sealwithin the hopper 4. In either instance, a seal is automaticallyprovided'at all times within the vertical conveyor, irrespective ofwhether the removal of lime is continuous or periodic.

Normally, lump carbide is used in acetylene generators, but in somecases finely-divided or dust carbide has been used, and the principlesof this invention may be employed in providing a seal during conveyanceof such dust carbide into the interior of the generator from a pointoutside thereof. For instance, the hopper 4 may replace one or both ofthe valves in the double valve arrangement previously referred to, sincethe tapered construction, or downwardly decreasing cross-sectional area,causes a slight packing and increase in density resulting in a veryeffective terial.

Although the gas seal provided by the disclosed apparatus has beendescribed with reference to the generation of acetylene, it will beunderstood that the principles of this invention may be utilized inother instances. Furthermore, while a particular form of apparatusadapted to carry out the method of this invention has been described, itwill be understood that various modifications may be made therein, suchas utilizing a conveyor which is not exactly vertical but onlysubstantially vertical, 1. e. sloping upwardly at a sufiicient angle sothat a gas-sealing column of finely-divided material, which material ispositively moved upwardly in the conveyor to a first predetermined leveltherein, will be auto-; matically formed and maintained in the conveyoras the material is pushed upwardly from the first predetermined level toa second predetermined level by only the force of the material beingpositively moved upwardly from beneath the "first predetermined level.The distance between the first and second predetermined levels, in allembodiments of the invention, should be suflicient to accommodatetherebetween an effective gas-sealing column of the finely-dividedmaterial. It will be apparent that only a portion or section of theconduit or conveyor system need be disposed substantially vertically inorder to provide the desired gas-sealing column of ma- It will also beunderstood that other forms of apparatus may be used which will comewithin the spirit and scope of this invention.

What is claimed is:

1. In apparatus for safely conveying finelydivided material between theinterior of a combustible gas generator and a point outside'suchgenerator, a conveyor housing disposed substantially verticallyand'having an outlet adjacent the upper end thereof; and means forpositively moving such finely-divided material upwardly in said conveyorhousing to a predetermined level which is a sufficient distance belowsaid outlet so that a gas-sealing column 'of such material will beautomatically maintained within said conveyor housing between saidpredetermined level and said outlet as such material is pushed upwardlyfrom said predetermined level to said outlet only by the force of thematerial being moved upwardly from beneath said predetermined level.

2. Apparatus for safely removing finely-divided dry lime residue from anacetylene gas generator,

comprising a gas-tight hopper operatively connected with said generatorand through which such residue passes downwardly; means for removingsuch residue from said hopper including a conveyor housing disposedsubstantially vertically and having an outlet adjacent the upper endthereof; a helicoid screw within said conveyor housing and terminatingat a predetermined level below said outlet; and means including a shaftfor rotating said screw whereby such residue is moved positivelyupwardly in said conveyor housing to said predetermined level which issufiiciently below said outlet so that a gas sealing column of suchresidue is automatically maintained between the top of said helicoidscrew and said outlet. v

3. In apparatus for safely conveying finelydivided dry lime residue froman acetylene generator installed within a generator room, an airtightconveyor housing disposed horizontally and operatively connected withthe lime outlet of said generator, said horizontal conveyor housingpassing through a wall of said generator room; an air-tight conveyorhousing disposed substantially vertically and outside said generatorroom, said vertical conveyor housing being operatively connected withsaid horizontal conveyor housing and provided with an outlet adjacentthe upper end thereof; means'within'said horizontal conveyor housing formoving said residue through said horizontal conveyor housing to saidvertical conveyor housing; and means within said vertical conveyorhousing for moving said residue upwardly through said vertical conveyorhousing, said last-mentioned means being 50 arranged as to effect apositive movement of said residue upwardly in said vertical conveyorhousing to a predetermined level which is a suflicient distanceg. belowsaid outlet so that a gas-sealing column of lime residue isautomatically maintained between said predetermined level and the upperend of said vertical conveyor housing.

4. In apparatus for safely conveying finelydivided material between theinterior of a combustible gas generator and a point outside suchgenerator, a hopper through which such material passes downwardly and inwhich such material is maintained at a predetermined level so as to forma gas seal; and means movable laterally in any direction as well aslongitudinally within said hopper for indicating the level of suchmaterial within said hopper through positive contact with such material,and for breaking incrustations of such material formed within saidhopper. 5. In apparatus for safely conveying finelydivided'materialbetween the interior of a combustible gas generator and a point outsidesuch generator, a hopper through which such material passes downwardlyand in which such material is maintained at a predetermined level so asto form a gas seal; means for indicating the level of such materialwithin said hopper and for breaking incrustations of such materialformed within said hopper through positive contact with tendingdownwardly through the wall of and into said hopper and a disk attachedto the lower end of said rod for contacting such material in saidhopper; and a joint connecting said rod and the wall of said hopper,said joint and said rod being so constructed and arranged that said rodand said disk are movablelaterally as well as longitudinally within saidhopper.

6. In apparatus for safely removing dry lime such material, said meanscomprising a rod ex residue from an acetylene generator, an air tighthopper operatively connected with said generatorand through which suchdry lime residue passes downwardly, such dry lime residue beingmaintamed at a predetermined level within said hopper so as to form agas seal; a movably mounted rod extending through the wall of saidhopper and downwardly into the interior thereof mounting meansconnecting said rod and the wall of said hopper and including a ball andsocket joint; a packing gland for said rod; and a disk attached to thelower end of said rod for contacting dry lime residue within said hopperwhereby incrustations of such residue within said hopper are broken andthe level of such residue within said hopper is positively determined inmaintaining a column of such residue of predetermined height within saidhopper to form a gas seal.

7. Apparatus for safely conveying substantially dry, finely-dividedmaterial between an enclosed reaction zone in which a combustible gas isgenerated arid a point outside such zone, comprising an enclosed conduitextending between such reaction zone and such outside point, at

4 least a portion oi-said conduit being substantially vertical; and saidconduit having an outlet ad- Jacent one end thereof; and means formoving said material throughsaid conduit, such moving dry lime residuefrom the generating zone of an.

acetylene generator, comprising an enclosed conduit leading fromsaid-generating zone to a point outside thereof and having an outletadjacent such outside point, at least a: portion 0! said canduit beingsubstantially vertical; and meansior moving said lime residue throughsaid conduit from said generating zone to said outside point,v

such moving means being so constructed and'arranged that said limeresidue is positively moved upwardly within saidsubstantially-verticalportion to a predetermined level which is sufllciently below said outletso that a gas=sealingcolumn o! b said lime residue will be automaticallymaintained between said predeterminedlevel and said outlet as said limeresiduefis pushed upwardly fromsaid predetermined level to said outlet.only by the force of the material being. positively moved upwardlyifrombeneath said predeter' mined level.

. MAURICE O'BRIAN.

